This study is one of a number of research components of the Stroke Data Bank Project. Based on prospectively collected patient data, a temporal description of stroke in evolution by type and site of lesion will be developed. The patients' clinical status determined by changes in Glasgow Coma Score, hemiparesis score, and stroke severity score identifies those cases that evolve. This study also attempts to identify factors that cause or contribute to stroke evolution. Some of these are: edema, shock, electrolyte imbalance, cardiovascular factors and cognitive problems. The accumulating patient data have been monitored periodically, and the first analyses of data will begin in FY '85.